Sainsmart LCD2004 vs Arduino Wireless SD Shield (I can't get 'em to play nice)

Other Hardware Displays
1

Hey guys.
I've got a presentation tomorrow, and it would be icing on the cake if I could implement this LCD into my project.

The project:
Thermostats in each room of the house.
Communicating back to the arduino,
which logs the temp-data and (hopefully) displays it real-time too.

For logging data I've got this: Arduino Wireless SD Shield

For displaying data I've got this: Stainsmart 20x4 Serial LCD
http://www.sainsmart.com/sainsmart-iic-i2c-twi-serial-2004-20x4-lcd-module-shield-for-arduino-uno-mega-r3.html

I set up the LCD following ianbren's post here: [SOLVED] I2C LCD - Setup instructions for 16x2 - Displays - Arduino Forum

the problem:
I can't get the SD card working (to log data) when I add in the code for the LCD.
I can get either one to work without the other, but they won't play well together.

Any suggestions?
I'll probably be pullin' another all-nighter tonight.
:0

Thanks.

2

[2 am UPDATE]:

turns out the problem was the size of my sketch.

on my Arduino Uno,
the SD card stopped functioning after ~22,500 bytes (of 32,256 available).
It functioned perfectly well at 22,400 bytes.

Weird.

Unfortunately all I have are Uno's, and I don't think creating an i2C link for an LCD screen is worth the time for me to learn how to do that. I'll shop for a duo or Mega in the AM if I can find one.

-Josh!

3

Sounds like something else is going on.
There is nothing magic that happens as 22.5k
Seems more likely you are running out of RAM and
by removing some of you code, your RAM usage dropped down.
Do you have lots of literal data like quoted strings, data tables
or data storage arrays or buffers?

--- bill

4

bperrybap:
Sounds like something else is going on.
There is nothing magic that happens as 22.5k
Seems more likely you are running out of RAM and
by removing some of you code, your RAM usage dropped down.
Do you have lots of literal data like quoted strings, data tables
or data storage arrays or buffers?

Yep... lots of 2D arrays.
Switching to the Mega solved my problems,
likely (as you mentioned) because the arduino mega has 8 KB of ram vs the uno's 2 KB.
thanks for the help.